JP2017009382A - Observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an observation device that can acquire information on the three-dimensional position of an observation target object.SOLUTION: The observation device includes: a linearly arranged optical fiber 32; an image sensor 21 disposed on one end of the optical fiber 32, which has a plurality of light receiving elements arranged in the range of the core of the optical fiber 32; a lens attached to the other end of the optical fiber 32, deflects a light from an observation target object S having entered the other end, into a direction of length of the optical fiber 32 and differentiates the positions of beams of light passing the inside of the core according to their incident angles; and a controller 13, which acquires an incident angle of a light to the lens according to the light receiving elements having received a light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an observation apparatus for observing an object such as a cell.

In general, a microscope is used to optically observe a minute observation object such as a cell. For example, Patent Document 1 discloses an apparatus that captures an image of an observation object magnified by a microscope using a digital camera.
Further, Patent Document 2 includes a vision circuit including an image sensor having a large number of pixels, and a holding member that is mounted on the image sensor of the vision circuit and causes an observation target to exist, and is an observation target on the holding member. An apparatus for acquiring an image of an object with an image sensor is disclosed.

JP 2004-70036 A JP 2008-129512 A

  In recent years, three-dimensional culture, which is an environment closer to the structure of a living body, has attracted attention in the field of cell research. In this three-dimensional culture, the cells are spatially dispersed inside a three-dimensional gel. In such a three-dimensional culture, it is desired to measure the spatial position of the cell. However, in a device using a microscope such as Patent Document 1, there is a limit to the distance that can be focused, and light is emitted by the gel. Spatial position measurement is difficult due to diffusion. Moreover, there is a limit to the observable gel thickness even when the position measurement is performed by placing the gel on the holding member using the apparatus described in Patent Document 2. Therefore, in both Patent Documents 1 and 2, it is difficult to acquire information that can appropriately grasp the position of the observation object that is arranged three-dimensionally.

  An object of this invention is to provide the observation apparatus which can acquire the information regarding the three-dimensional position of an observation target object.

(1) The observation apparatus according to the present invention is
Optical fibers arranged in a straight line;
A position of a light beam that is attached to one end of the optical fiber, refracts light from the observation object incident on the one end in a direction along the length direction of the optical fiber, and passes through the core according to the incident angle of the light. A lens that changes
An image sensor provided on the other end side of the optical fiber and having a plurality of light receiving elements within the end face range of the core for receiving light that has passed through the core;
And a control device that acquires an incident angle of the light with respect to the lens in accordance with the light receiving element that has received the light.

  In the observation apparatus configured as described above, light from the observation object incident on the lens is refracted in a direction along the length direction of the optical fiber, passes through the core of the optical fiber, and is received by the light receiving element. Since the lens changes the position of the light beam that passes through the core of the optical fiber according to the incident angle of light, the light receiving element that receives the light can also be changed, and the control device can respond to the light receiving element that receives the light. The incident angle of light can be acquired. Therefore, according to the observation apparatus of the present invention, it is possible to grasp the three-dimensional position of the observation object using the acquired incident angle. The observation object can be, for example, a living cell, and in this case, the observation object may be a cell constituting a tissue such as a brain or an organ in the living body, or a cell cultured outside the living body. May be.

(2) The control device obtains incident angles of light from the same observation object incident on the lens at a plurality of positions in the length direction of the optical fiber, and a plurality of positions of the lens; It is preferable to acquire the position of the observation object based on the relationship with the acquired plurality of incident angles.
With such a configuration, not only the incident angle of light with respect to the lens but also the position of the observation object can be acquired.

(3) It is preferable that the control device acquires a distance from the lens to the observation target based on a relationship between the position of the lens and the position of the observation target.
With such a configuration, it is possible to acquire not only the incident angle of light with respect to the lens and the position of the observation object, but also the distance from the lens to the observation object.

(4) The control device is emitted from the observation object based on a relationship between a distance from the lens to the observation object and an intensity of light incident on the lens and received by the light receiving element. It is preferable to acquire the intensity of light.
With such a configuration, it is possible to grasp the intensity of light emitted from the observation object in addition to the three-dimensional position of the observation object.

(5) The control device includes a relationship between a distance from the lens to the observation object and an intensity of light incident on the lens and received by the light receiving element, and an incident angle of light with respect to the lens and the lens. The intensity of light emitted from the observation object can be acquired based on the relationship with the intensity of light incident on the light and received by the light receiving element.
With such a configuration, in addition to the three-dimensional position of the observation object, the intensity of light emitted from the observation object can be accurately grasped in consideration of the incident angle.

(6) The observation apparatus further includes a storage unit that stores information indicating a relationship between an intensity of light received by the light receiving element and a distance from the lens to the observation target,
The control device acquires a distance from the lens to the observation object based on the intensity of light received by the light receiving element and the information, and the observation object based on the distance and the incident angle. It is preferable to acquire the position.
When the intensity of light of the observation object is known, the relationship between the intensity of the light received by the light receiving element and the distance from the lens to the observation object can be acquired in advance. The distance from the lens to the observation object can be obtained by storing the information in the storage unit and taking this information into account, and the position of the observation object can be obtained based on the distance and the incident angle.

(7) It is preferable that the optical fiber includes a cylindrical protective tube that is inserted so as to be movable in the length direction and is capable of transmitting light from the observation object.
According to this configuration, for example, a protective tube is inserted into a gel in which cells to be observed in vitro are cultured, or into a tissue containing cells to be observed in vivo, and an optical fiber is inserted in the protective tube. By moving along the length direction, the position of the optical fiber can be changed in a state in which invasion to the living body, the gel, and the cells contained therein is prevented.

(8) Preferably, a plurality of the optical fibers are provided in parallel.
With such a configuration, information regarding a three-dimensional position can be acquired for a plurality of observation objects dispersed in a wide range.

It is the schematic which shows the observation apparatus which concerns on 1st Embodiment. It is sectional drawing which shows a part of observation apparatus. It is explanatory drawing which shows refraction of the light which injects into a lens. It is explanatory drawing which shows the relationship between the incident angle of the light with respect to a lens, and the distance to an observation target object. It is a graph which shows the relationship between the incident angle of the light with respect to a lens, and the light reception position in a light receiving element. It is a graph which shows the relationship between the distance between a lens and an observation target object, and the light reception intensity | strength of a light receiving element. It is sectional drawing which shows a part of observation apparatus which concerns on 2nd Embodiment. It is explanatory drawing which shows the relationship between the incident angle of the light with respect to a lens, and the distance to an observation target object. It is a graph which shows the relationship between the distance between the lens and observation object in 3rd Embodiment, and the light reception intensity | strength of a light receiving element.

Hereinafter, more detailed embodiments of the cell state detection apparatus will be described.
[First Embodiment]
FIG. 1 is a schematic diagram illustrating an observation apparatus according to the first embodiment.
The observation apparatus 10 according to the present embodiment acquires an image and a position of the cell S by receiving light emitted from the cell S three-dimensionally cultured in the three-dimensional gel G. The gel G shown in FIG. 1 is formed in a cylindrical shape, and is cultured with a large number of cells S dispersed therein. The cell S is labeled with, for example, a fluorescent dye and emits fluorescence when excited.

  The observation device 10 includes a vision circuit 11, a light introducing unit 12, a control device 13, a display device 14, and a lifting stage 15. The vision circuit 11 includes an image sensor 21 having a large number of minute light receiving elements (pixels) 22 arranged vertically and horizontally in a grid pattern, an image processing circuit 23 to which a signal captured by the image sensor 21 is input, and the like. Yes. A CCD, CMOS, or the like is used for the light receiving element 22 of the image sensor 21. The size (diameter) of the cell S as the observation object is about 5 μm to 100 μm, whereas the size of one pixel of the image sensor 21 is about 1 μm to 50 μm. it can.

  The image processing circuit 23 performs various types of processing of the signals captured by the image sensor 21, such as image generation processing and resolution adjustment processing. The image processing circuit 23 may include a storage unit that stores signals. As the vision circuit 11, for example, the one described in Patent Document 2 can be used.

FIG. 2 is a cross-sectional view showing a part of the observation apparatus 10.
As shown in FIGS. 1 and 2, the light introducing unit 12 includes a base 31, an optical fiber 32 erected on the base 31, and a lens 33 provided at the tip of the optical fiber 32. Yes.
The base 31 is formed in a disc shape with silicone rubber or the like using PDMS or the like, and is disposed on the image sensor 21 of the vision circuit 11.

  The optical fiber 32 is linearly arranged with its length direction directed in the vertical direction, and its lower end is fixed to the base 31. Further, as shown in FIG. 1, a large number of optical fibers 32 are provided. Specifically, the multiple optical fibers 32 are arranged side by side vertically and horizontally in the range above the image sensor 21 in a parallel relationship. The tip of the optical fiber 32 is inserted into the gel G. The interval between the adjacent optical fibers 32 can be set to about 200 μm, for example.

  As shown in FIG. 2, the optical fiber 32 includes a core 41 that forms a central portion and a clad 42 that forms an outer peripheral portion. The light introduced into the optical fiber 32 travels through the core 41. The light taken in from the upper end of the optical fiber 32 travels downward and is received by one or more light receiving elements 22 constituting the image sensor 21. A plurality of light receiving elements 22 are provided in the range of the lower end surface of the core 41 in each optical fiber 32.

  The lens 33 is a concave lens having a concave portion 33 a on the upper surface, and is fixed to the upper end of the optical fiber 32. The lens 33 refracts incident light and introduces it into the core 41 of the optical fiber 32.

  The lens 33 has the following characteristics. First, as shown in FIG. 3, the lens 33 refracts incident light in a direction along the length direction of the optical fiber 32, that is, in a vertical direction. Therefore, in the core 41 of the optical fiber 32, the light travels substantially vertically downward, and almost no refraction occurs at the boundary surface with the clad 42. Note that W1 in FIG. 3 indicates a range in which light from the cell S can enter the lens 33.

  The lens 33 changes the position of the light beam B passing through the core 41 according to the incident angle θ of the light. Specifically, the larger the incident angle θ of the light, the light beam B passes through a position away from the center of the core 41. Since a plurality of the light receiving elements 22 of the image sensor 21 are provided within the range of the lower end surface of the core 41, the light receiving elements 22 that receive light change depending on the position of the light beam B. Therefore, the incident angle θ to the lens 33 can be obtained according to the light receiving element 22 that has received the light. In addition, an image of the cell S can be generated by a signal from the light receiving element 22 that has received the light.

FIG. 5 is a graph showing the relationship between the incident angle of light with respect to the lens 33 and the light receiving position of the image sensor 21. The horizontal axis of this graph is the light receiving position, and corresponds to the distance r from the center of the core 41 as shown in FIG.
As is clear from this graph, as the incident angle with respect to the lens 33 increases, the image sensor 21 receives light at a position farther from the center of the core 41. Information on the relationship between the incident angle and the light receiving position corresponding to the graph of FIG. 5 is stored in a storage unit of the control device 13 described later.

  The control device 13 is configured by a personal computer, for example. The control device 13 includes a calculation unit such as a CPU, a storage unit such as a RAM, a ROM, and a hard disk, an input / output interface, and the like. The control device 13 performs processing such as transmission / reception of information with the image processing circuit 23 of the vision circuit 11, operation control of the vision circuit 11, processing of acquired information, and storage of information. Further, as will be described later, the control device 13 performs processing such as acquisition of information regarding the position of the cell S and acquisition of information indicating the light intensity emitted by the cell S. These processes in the control device 13 are realized by the calculation unit executing the computer program stored in the storage unit.

  The display device 14 includes a CRT monitor and a liquid crystal monitor, and is connected to the input / output interface of the control device 13. In addition to the image photographed by the vision circuit 11, information indicating the position of the cell S, information indicating the light intensity, and the like are displayed on the display device 14.

  The elevating stage (elevating device) 15 moves the vision circuit 11 and the light introducing unit 12 in the vertical direction. The amount of the optical fiber 32 inserted into the gel G can be adjusted by moving the light introducing portion 12 up and down. The operation of the elevating stage 15 is controlled by the control device 13. Further, the position information in the vertical direction of the optical fiber 32 (or the lens 33) is input from the elevating stage 15 to the control device 13. The position information in the vertical direction of the optical fiber 32 can be coordinates with a certain position as the origin. The origin can be set, for example, on the center line of the optical fiber 32 and at a position where the tip of the lens 33 starts to be inserted into the gel G (that is, the position of the lower end surface of the gel G).

[Details of Processing in Control Device 13]
The control device 13 acquires information regarding the position of the cell S. Specifically, as shown in FIG. 4, the coordinates (Zf, Rf) of the cell S with respect to the origin O are acquired. And in order to acquire the coordinate (Zf, Rf) of the cell S, the incident angle ((theta) a, (theta) b) of the light with respect to the lens 33 is acquired. Further, the distance (Da, Db) from the lens 33 to the cell S is also acquired. FIG. 4 shows two-dimensional coordinates having a Z-axis and an R-axis with respect to the origin O, but in actuality, the coordinates are three-dimensional coordinates including an axis in the paper penetration direction. In the present embodiment, for easy explanation, acquisition of the position of the cell S on the two-dimensional coordinates defined by the Z-axis and the R-axis among the three-dimensional coordinates will be described.

  FIG. 4 shows a state in which light from one cell S is incident when the optical fiber 32 is moved in the vertical direction and disposed at two positions, a high position and a low position. The coordinate of the lens when the optical fiber 32 is at the high position is (Zha, 0), and the coordinate of the lens 33 when the optical fiber 32 is at the low position is (Zhb, 0). First, the control device 13 shows the incident angle θa of light with respect to the lens 33 when the optical fiber 32 is at a high position and the incident angle θb when it is at a low position as shown in FIG. Get based on relationships.

Information about the Z coordinates (heights) Zha and Zhb of the optical fiber 32 at the high position and the low position is input from the lifting stage 15 by the control device 13.
Next, the control device 13 acquires the coordinates (Zf, Rf) of the cell S from the incident angles θa, θb at the two upper and lower positions and the heights Zha, Zhb at the two upper and lower positions. Specifically, the Z coordinate Zf of the cell S can be approximately obtained by the following equations (1) and (2).
Zf≈Zha + Rf × tan (90 ° −θa) (1)
Zf≈Zhb + Rf × tan (90 ° −θb) (2)

  Since Zha, Zhb, θa, and θb are all known, the coordinates (Zf, Rf) of the cell S can be calculated from the two equations (1) and (2). The above formulas (1) and (2) are the formulas assuming that the Z coordinate of the position where light is incident on the lens 33 is the deepest position of the concave portion 33a of the lens 33 and the R coordinate is zero. However, if the coordinates of the incident position are set more accurately, the coordinates (Zf, Rf) of the cell S can be obtained more accurately.

Further, the distances (optical path lengths) Da and Db from the cell S to the lens 33 can be approximately obtained by the following equations (3) and (4).
Da≈ {(Zf−Zha) ² + Rf ² } ^1/2 (3)
Db≈ {(Zf−Zhb) ² + Rf ² } ^1/2 (4)

By the above procedure, the incident angles θa and θb of light with respect to the lens 33, the position (Zf, Rf) of the cell S, and the distances Da and Db from the lens 33 to the cell S can be acquired. The three-dimensional position of the cell S can be obtained by performing the same procedure as described above with respect to the axis in the paper penetration direction and the Z axis in FIG.
Moreover, since the observation apparatus 10 includes a large number of optical fibers 32 and lenses 33 as the light introduction part 12, it is possible to grasp the three-dimensional position of the entire cell S in the gel G.

  The control device 13 also acquires the intensity of light emitted from the cell S. Therefore, the control device 13 acquires the relationship between the distance from the lens 33 to the cell S and the light intensity (%) (light intensity ratio) using the cells S present in the gel G as shown in FIG. To do. Specifically, the control device 13 targets the cell S located directly above the optical fiber 32, and distances D1 to D4 from the lens 33 to the cell S at a plurality of positions (two or more) in the vertical direction, The intensities I1 to I4 of the light incident from the position lens 33 and received by the light receiving element 22 are acquired. And the control apparatus 13 fits the curve C by regression analysis etc. from the relationship between the distances D1-D4 and the light intensity I1-I4. The control device 13 generates a graph of light intensity (%) (light intensity ratio) in which the light intensity Ix when the distance becomes 0 is 100% according to the curve C.

The control device 13 obtains the distance (optical path length) D from the lens 33 to the cell S using the equations (3) and (4) as described above, and then the light intensity ratio I _D corresponding to the distance _D. (%) Is determined based on the graph of curve C (see FIG. 6). The value of the light intensity ratio I _D (%) is 100% when the distance between the lens 33 and the cell S is 0, and decreases as the distance increases. That is, the light intensity ratio I _D (%) is a value that varies depending on the distance D.

When light from the cell S enters the lens 33, part of the light is absorbed by the lens 33, and the intensity of light received by the light receiving element 22 also changes. This light intensity changes depending on the optical path length inside the lens 33, and this optical path length changes depending on the incident angle with respect to the lens 33. Therefore, the control device 13 obtains a light intensity ratio I _θ (%) in consideration of a change in light intensity due to transmission through the lens 33 by the following equation (5).

I _θ = {1-A (1-cos α)} × 100 (5)
However, α = tan ⁻¹ {sin θ / (n−cos θ)}
A is the extinction coefficient of the lens 33, and n is the refractive index of the lens 33.

The value of the light intensity ratio I _θ (%) is 100% when the incident angle θ is 0 °, and decreases as the incident angle θ increases. That is, the light intensity ratio I _θ (%) is a value that varies depending on the incident angle θ.

Then, the control device 13 calculates the light intensity ratio of the light received by the light receiving element 22 from the light intensity ratio I _D (%) depending on the distance D and the light intensity ratio I _θ (%) depending on the incident angle θ. I _ratio (%) is _{calculated |} required by the following formula _| equation (5).
I _ratio (%) = I _D (%) × I _θ (%) / 100 (6)

Further, the control device 13 obtains the intensity I _real of light emitted from the cell S by the following equation (7).
I _real = I _detect / I _ratio (%) × 100 (7)
Here, I _detect is the intensity of light received by the light receiving element 22.

As described above, the intensity of light emitted from the cell S can be obtained in consideration of both the distance D from the lens 33 to the cell S and the incident angle θ of light.
In the above, since the change in the intensity of light depending on the incident angle θ is smaller than the change in the intensity of light depending on the distance D, the above equation (7) is expressed as I _ratio (%) = I _D (% ), And the intensity of light emitted from the cell S can be obtained considering only the change in light intensity depending on the distance D.

  In the observation apparatus 10 having the above-described configuration, the light introduction unit 12 is merely placed on the vision circuit 11, so that the vision for observing other cells S can be obtained by replacing only the light introduction unit 12. The circuit 11 can be used.

  The observation apparatus 10 of the above embodiment is not the three-dimensional culture gel G, but directly inserts the optical fiber 32 and the lens 33 of the light introducing section 12 into a living tissue, for example, the brain, etc. It is possible to acquire information on the three-dimensional position of the light and information on the light intensity.

[Second Embodiment]
FIG. 7 is a cross-sectional view showing a part of the observation apparatus according to the second embodiment.
The observation apparatus 10 according to the second embodiment includes a protective tube 50 into which the optical fiber 32 of the light introducing unit 12 is inserted. The protective tube 50 is formed of a material that can transmit light from the cells S, for example, transparent glass or a synthetic resin material. The protective tube 50 is placed in a state of being inserted into the gel G.

  In the present embodiment, the protective tube 50 exists outside the optical fiber 32, and light having a small incident angle is reflected by the protective tube 50, so that the light from the cells S can enter the lens 33. Is limited to a predetermined range W2 (see FIG. 7). Therefore, it is possible to prevent the light of a large number of cells S from entering one optical fiber 32 and to easily grasp the three-dimensional position of the cells S.

Also in the present embodiment, as shown in FIG. 8, the incident angles θa and θb, the position of the cell S (coordinates (Zf, Rf)), the distances Da and Db, and the light intensity are performed in the same procedure as in the first embodiment. _Ireal etc. can be acquired. The position of the cell S (coordinates (Zf, Rf)) and the distances Da, Db are obtained after taking into account the refraction of light transmitted through the protective tube 50. However, when the graph (curve C) corresponding to FIG. 6 is obtained, the light from the cells S existing just above the optical fiber 32 cannot be incident, so the light from the cells S in the predetermined range W2 And a graph can be generated by considering the reflectance by the protective tube 50, the diffusion coefficient of the gel G, and the like.

In the present embodiment, since the optical fiber 32 is inserted into the protective tube 50, the invasion to the cells S and the gel G (tissue) when the optical fiber 32 is moved in the vertical direction can be reduced. it can.
In addition, since the optical fiber 32 and the lens 33 constituting the light introducing portion 12 do not directly contact the gel G, the light introducing portion 12 can be used for observation of other cells S.

[Third Embodiment]
In the first embodiment, the position of the cell S and the distances Da and Db from the lens 33 to the cell S are acquired by moving the optical fiber 32 and the lens 33 in the vertical direction. In the embodiment, the distance D is acquired without moving the optical fiber 32 and the lens 33 in the vertical direction. However, in the present embodiment, it is assumed that the intensity of light emitted from the cell S is known.

  When the light emitted from the cell S is known, the distance from the lens 33 to the cell S (vertical distance) and the intensity (%) of light received by the light receiving element 22 (light intensity ratio) as shown in FIG. Can get a relationship. In the present embodiment, information about such a relationship is stored in advance in the storage unit of the control device 13.

  Then, the control device 13 converts the intensity of the light emitted from the cells S in the gel G and received by the light receiving element 22 into a light intensity ratio from the relationship with the light intensity of the known cells S, as shown in FIG. The distance from the lens 33 to the cell S is acquired by taking into account the relationship shown. Then, the three-dimensional position of the cell can be obtained from the distance and the incident angle. Note that the acquired distance may be corrected using the relationship of Expression (5) in order to reflect the change in light intensity due to the incident angle.

With the configuration as described above, the distance from the lens 33 to the cell S can be obtained without moving the optical fiber 32 in the vertical direction as in the first embodiment, and the processing by the control device 13 is simplified. Can be realized.
In the third embodiment, since the change in the light intensity at the incident angle is smaller than the change in the light intensity due to the distance, only the relationship in FIG. 9 is performed without performing the correction using the relationship of Expression (5). The distance from the lens 33 to the cell S may be acquired.

The present invention is not limited to the above-described embodiment, and can be modified within the scope of the invention described in the claims.
For example, the observation apparatus according to the present invention may include only one optical fiber. Further, a plurality of optical fibers may be arranged on a straight line. Further, a large number of optical fibers may be randomly arranged.

The raising / lowering stage is not limited to one that automatically raises and lowers the vision circuit and the light introduction unit, but may be one that raises and lowers manually.
As the observation object in the present invention, a substance other than a cell can be adopted as long as it is a microscopic body that emits light.

10: Observation device 13: Control device 21: Image sensor 22: Light receiving element 32: Optical fiber 33: Lens 41: Core S: Cell (observation object)
Da, Db: Distance θa, θb: Incident angle

Claims (8)

Optical fibers arranged in a straight line;
A position of a light beam that is attached to one end of the optical fiber, refracts light from the observation object incident on the one end in a direction along the length direction of the optical fiber, and passes through the core according to the incident angle of the light. A lens that changes
An image sensor provided on the other end side of the optical fiber and having a plurality of light receiving elements within the end face range of the core for receiving light that has passed through the core;
An observation apparatus comprising: a control device that acquires an incident angle of light with respect to the lens according to the light receiving element that has received light.   The control device respectively obtains incident angles of light from the same observation object incident on the lens at a plurality of positions in the length direction of the optical fiber, and acquires the plurality of positions of the lens and the plurality of acquired positions. The observation apparatus according to claim 1, wherein the position of the observation object is acquired based on a relationship with an incident angle of the observation object.   The observation device according to claim 2, wherein the control device acquires a distance from the lens to the observation object based on a relationship between the position of the lens and the position of the observation object.   The control device, based on the relationship between the distance from the lens to the observation object and the intensity of the light incident on the lens and received by the light receiving element, the intensity of the light emitted from the observation object The observation apparatus according to claim 3, wherein   The control device includes a relationship between a distance from the lens to an observation object and an intensity of light incident on the lens and received by the light receiving element, and an incident angle of light with respect to the lens and incident on the lens. The observation apparatus according to claim 3, wherein the intensity of light emitted from the observation object is acquired based on a relationship with the intensity of light received by the light receiving element. A storage unit that stores information indicating the relationship between the intensity of light received by the light receiving element and the distance from the lens to the observation object;
The control device acquires a distance from the lens to the observation object based on the intensity of light received by the light receiving element and the information, and the observation object based on the distance and the incident angle. The observation apparatus according to claim 1, which acquires the position of. The observation apparatus according to claim 1, wherein the optical fiber includes a cylindrical protective tube that is inserted so as to be movable in a length direction and is capable of transmitting light from the observation object. .   The observation apparatus according to claim 1, comprising a plurality of the optical fibers in parallel.

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